POS0153 MRI SPINAL LESIONS IN PATIENTS WITHOUT MRI OR RADIOGRAPHIC LESIONS IN THE SACROILIAC JOINTS TYPICAL OF AXIAL SPONDYLOARTHRITIS
Authors: W. P. Maksymowych, M. Østergaard, X. Baraliakos, P. Machado, S. J. Pedersen, U. Weber, I. Eshed, M. De Hooge, J. Sieper, D. Poddubnyy, M. Rudwaleit, D. Van der Heijde, R. B. M. Landewé, R. G. Lambert
Journal: Annals of the Rheumatic Diseases (2022)

Background There are limited data as to the frequency of spinal lesions on MRI in patients without MRI or radiographic features typical of sacroiliac joint (SIJ) disease and to what degree spine MRI might enhance diagnostic evaluation. Objectives To assess the frequency of MRI lesions of the spine in the ASAS-Classification Cohort according to the presence of MRI SIJ lesions typical of axSpA and/or radiographic sacroiliitis (mNY+). Methods MRI spine lesions were recorded by 9 central readers in an eCRF that captures global assessment of the spine (“Is the MRI consistent with axSpA: yes/no”) (yes=MRI global spine+) and detailed anatomical-based scoring of each discovertebral unit plus lateral and posterior structures. Independently, readers globally assessed SIJ scans for active and/or structural lesions typical of axSpA. We compared the frequency of MRI global spine+ and frequencies of different types of spinal lesions according to the presence/absence of axSpA on global evaluation of SIJ scans by ≥5 of 9 readers (MRI global SIJ+) and mNY+ sacroiliitis using Fisher’s exact test. Analysis was also stratified by rheumatologist diagnosis. Results Among 51 cases with SIJ as well as spine MRI scans and radiographs of the SIJ,19 (37.3%) had MRI global SIJ+, and 12 (23.5%) and 7 (13.7%) had MRI global spine+ by ≥2 and ≥5 reader agreement, respectively. MRI global spine+ occurred significantly more frequently in the presence of mNY+ sacroiliitis and MRI global SIJ+ but was also recorded in 4 of 32(12.5%) (≥2 readers) and 1 of 32(3.4%) (≥5 readers) cases that were MRI global SIJ- and x-ray negative, all 4 cases being diagnosed with axSpA. Moreover, vertebral corner BME lesions, but not spinal structural lesions, were significantly more frequent in MRI global SIJ- cases that had been clinically diagnosed as axSpA versus non-axSpA (Table 1). Table 1. Frequency of Spinal MRI lesions According to SIJ Imaging Positive for AxSpA MRI Spinal Lesions, N (%) MRI global SIJ+ (n=19) MRI global SIJ- (n=32) P value MRI global SIJ+ and/or mNY+ (n=22) MRI global SIJ- and mNY- (n=29) P value MRI global SIJ- and SpA Diagnosis+(n=17) MRI global SIJ- and SpA Diagnosis- (n=15) P value MRI global consistent with axSpA (≥2/9 readers agree) 8 (42.1%) 4 (12.5%) 0.04 8(36.4%) 4(13.8%) 0.10 4 (23.5%) 0 (0%) 0.10 MRI global consistent with axSpA (≥5/9 readers agree) 6 (31.6%) 1 (3.1%) 0.01 6 (27.3%) 1 (3.4%) 0.03 1 (5.9%) 0 (0%) 1.0 VC BME ≥1 9 (47.4%) 15 (46.9%)46.9% RT 62.5% CT 29.4% GT 1.0 10(45.5%) 14(48.3%) 1.0 11 (64.7%) 4 (26.7%) 0.04 VC BME ≥2 6 (31.6%) 10 (31.3%)31.2% RT 55.6% CT 19.6% GT 1.0 6(27.3%) 10(34.5%) 0.76 9 (52.9%) 1 (6.7%) 0.007 VC BME ≥3 6 (31.6%) 7 (21.9%)21.9% RT 53.8% CT 13.7% GT 0.52 6(27.3%) 7(24.1%) 1.0 7 (41.2%) 0 (0%) 0.008 VC BME ≥4 5 (26.3%) 5 (15.6%) 0.47 5(22.7%) 5(17.2%) 0.73 5 (29.4%) 0 (0%) 0.046 Vertebral Endplate BME ≥1 2 (10.5%) 3 (9.4%) 1.0 2(9.1%) 3(10.3%) 1.0 2 (11.8%) 1 (6.7%) 1.0 Lateral vertebral BME 3 (15.8%) 3 (9.4%) 0.66 3(13.6%) 3(10.3%) 1.0 3 (17.6%) 0 (0%) 0.23 Facet BME ≥1 4 (21.1%) 1 (3.1%)3.1% RT 20.0% CT 2.0% GT 0.06 4(18.2%) 1(3.4%) 0.15 1 (5.9%) 0 (0%) 1.0 Posterior BME ≥1 5 (26.3%) 2 (6.3%) 0.09 5(22.7%) 2(6.9%) 0.22 1 (5.9%) 1 (6.7%) 1.0 VC Fat ≥1 8 (42.1%)42.1% RT 44.4% CT 15.7% GT 10 (31.3%)31.2% RT 55.6% CT 19.6% GT 0.55 8(36.4%) 10(34.5%) 1.0 5 (29.4%) 5 (33.3%) 1.0 VC Fat ≥2 7 (36.8%) 5 (15.6%) 0.10 7(31.8%) 5(17.2%) 0.32 3 (17.6%) 2 (13.3%) 1.0 VC Fat ≥3 6 (31.6%)31.6% RT 66.7% CT 11.8% GT 3 (9.4%) 0.06 6(27.3%) 3(10.3%) 0.15 1 (5.9%) 2 (13.3%) 0.59 VC Fat ≥4 6 (31.6%) 1 (3.1%) 0.01 6(27.3%) 1(3.4%) 0.03 0 (0%) 1 (6.7%) 0.47 Lateral Fat ≥1 6 (31.6%) 2 (6.3%) 0.04 6(27.3%) 2(6.9%) 0.06 0 (0%) 2 (13.3%) 0.21 Erosion ≥1 3 (15.8%) 2 (6.3%) 0.35 3(13.6%) 2(6.9%) 0.64 1 (5.9%) 1 (6.7%) 1.0 Bone Spur ≥1 4 (21.1%) 5 (15.6%) 0.71 4(18.2%) 5(17.2%) 1.0 4 (23.5%) 1 (6.7%) 0.34 Ankylosis ≥1 2 (10.5%) 0 (0%) 0.13 2(9.1%) 0(0%) 0.18 0 (0%) 0 (0%) - Conclusion Spinal lesions on MRI indicative of axSpA per majority read occurred in about 3% of patients without positive imaging in the SIJ. Frequency of spinal BME lesions was higher in cases with negative SIJ imaging but clinically diagnosed with axSpA. Disclosure of Interests None declared